This choropleth map displays the world’s countries, each filled with a light green color that turns red on hover, while the ocean remains blue. It uses D3 v5 and TopoJSON to load world-atlas data, combining a TSV file for country names with a JSON topology for geographic boundaries. The map is rendered with an SVG using a natural Earth projection via `d3.geoPath`, and interactive panning and zooming are enabled through `d3.zoom`.